Constant delivery radial piston pump



J 1934- E. K. BENEDEK ET AL 1,964,245

CONSTANT DELIVERY RADIAL PISTON PUMP Filed Sept. 22. 1931 4 Sheets-Sheet l HIIIIHII Zmnentors,

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J1me 1934. E. K. BENEDEK El AL 1,964,245

CONSTANT DELIVERY RADIAL PISTON PUMP Filed Sept. 22, 1931 4 Sheets-Sheet f F ii I If {I P5355 1 I I 57 7 J7 V 1 I 6 f2 w J g 55 Gttorneg&

June 26, 1934. E. K. BENEDEK ET AL 1,954,245

CONSTANT DELIVERY RADIAL PISTON PUMP Filed Sept. 22, 1 931 4 Sheets-Sheet 4 0 I7 I 9 Wi 53 5g fi g3 I J2 ,7 I III Zhwentors, z'zeziri /TS e wmwmzzmmzllw 6y M4, 5 w

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Patented June 26, 1934 UNITED STATES PATENT OFFICE Elek K. Benedek and Howard F. MacMillin, Mount Gilead, Ohio, assignors to The Hydraulic Press Manufacturing Company, Mount Gilead, Ohio Application September 22, 1931, Serial No. 564,405

4 Claims.

The invention relates generally to radial piston pumps of the type wherein are provided operative control valve equipments which serve to control the fluid suction and expulsion effects of the 6 piston operation and primarily has for its object to provide a novel pump construction of the type stated which is capable of developing high working pressures and of effecting constant delivery, and which, while simple 'and compact in its nature, is at the same time rugged and adapted for rendering long and efficient service.

The conventional forms of this type of pump of which We are aware are ineflicient and incapable of high speed operation developing high working pressures due to the faulty piston and valve construction and arrangements employed therein and which are, because of their construction and arrangement, subjected to unnecessary operating strains and wear, greatly reducing the B0 efllciency in operation and also the longevity of the pump. The now common piston andvalve arrangements also consume much unnecessary space and thwart eiiorts at producing desirably compact pumping units.

With a view to remedying the conditions mentioned, our invention embodies among its objects the provision of a novel elastic piston construction and arrangement, a novel balancedcontrol valve construction and arrangement, a novel arrangement' of fluid intake and outlet chambers, and novel operating devices for the pistons and the valves, all being arranged to combine and cooperate in providing an unusually compact and highly eflicient constant delivery pump.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects and ends the invention still further resides in the novel details of construction, the combination and arrangement of parts, all of which will be first fully described in the following detailed description, then be particularly pointed out in the appended claims, reference being had to the accompanying drawings, in which:

Figure 1 is a central longitudinal section of a pump embodying our invention,' parts being shown in elevation.

Figures 2 and 3 are vertical cross sections taken on the lines 2-2 and 33 respectively on Figure 1.

Figure 4 is a diagrammatic view illustrating the relative positions of the piston and valve operating eccentrics.

Figure 5 is a detail vertical cross section of the pump casing taken through. the plane in 55 which the valve axes lie.

Figure 6 is a detail cross section taken on the line 66 on Figure 5.

Figures 7 and 8 are inverted plan and central longitudinal sectional views respectively of one of the piston cross heads.

Figure 9 is a detail side elevation of one of the piston screws.

Figure 10 is a detail sectional view of one of the piston sleeves.

Figure 11 is a detail side elevation of one of the control valves.

In the drawings in which like numerals of reference indicate like parts in all of the figures, 5 designates the pump casing which includes an axial bore 6 and a counter-bore '1, the former being closed by an end plate 8 secured as at 9 to one end of the casing 5, and the latter by an end plate 10 secured as at 11 to the other end of the casing 5.

' The casing body 5 includes an annular delivery fluid chamber 12 and an annular suction fluid chamber 13, said chambers being concentrically arranged in a common plane as shown in Figures 1 and 3. The chamber 12 communicates through an intake port 14 with the inlet pipe 15 which is secured as at 16 to the casing, and the chamber 13 communicates through the outlet duct 17 with an outlet pipe 18 which is secured as at 19 to the casing. The casing 5 also is provided with a plurality of radial valve bores 20 disposed in the plane of the fluid chambers 12 and 13 and spaced equidistantly about the axis of the casing. The valve bores 20 communicate between the fluid chambers 12 and 13, at their inner ends open into the casing bore 6, and are closed at their outer ends by cup plugs 21 which engage threaded bosses 22 surrounding said bores as shown in Figures 1 and 3 of the drawings. The portion of each bore extending through the casing wall separating the chambers 12 and 13 is equipped, at the end thereof communicating with a respective fluid chamber, with an annular recess or relief port 23 surrounding said bore portion.

The casing 5 also is provided with a plurality 1 of radial piston bores or cylinders 24 disposed in the central plane of the counter bore '7 and spaced equidistantly about the axis of the casing. It should be understood that one such bore 24 is provided for each valve bore 20 and the cooperation of these equipments will become apparent as the description progresses. The bores 24 are closed at their outer ends by plugs 25 and a duct 26 aflords communication between the outer end of each of the bores 24 and the portion intervening the recesses or relief ports 23 of the associated valve bore 20.

The details of construction of the pump casing described above are best shown in Figures 1, 2, 5 and 6.

An impeller shaft 2'7 is provided and has rotative bearing in anti-friction bearings 28 and 29 supported respectively in the casing 5 and in the end plate 10. The free end of the impeller shaft is extended through a gland 30 provided in the end plate 8 so that it may be conveniently connected with any suitable driving means not shown. The impeller shaft is equipped with a valve operating eccentric portion 31 and a piston operating eccentric portion 32, the portion 31 being positioned 90 degrees ahead in phase relation to the eccentric portion 32 for a purpose that will become apparent as the. description progresses.

A pistonoperating ring 33 is operable in the chamber provided by the casing counter-bore 7 and has rotative bearing on anti-friction bearings 34 supported by the piston operating eccentric portion 32. The ring 33 does not rotate and it be readily understood that its axis or cenis caused to follow a circular orbital path by reason of the support of said ring upon the rotating eccentric portion 32.

The ring 33 is provided with an annular recess 35, the opposed faces of the defining walls of which are provided with opposed pairs of tangentiaily disposed grooves 36. The peripheral metal remaining after the formation of the grooves 36 is slotted as at 37 to permit projection and movement of the pistons and the inner and outer wall faces of the grooves provide piston unit thrust surfaces 38 and suction pull effecting surfaces 39.

A piston unit cooperates with each bore or cylinder 24 and its associated set of grooves 36 and each piston unit compriss a cylinder body portion 40 reciprocable in and projecting radially from its respective bore and a T-head or cross head portion 41 which is slidable in the associated set of grooves '36.

Each piston unit cross head is in the nature of a flat rectangular block proportioned to slidably fit the receiving grooves 36 and having the face thereof opposed to the associated thrust face 38 of the ring 33 equipped with a central plane bearing surface 42 and a slightly inclined bearing surface 43 inclined from center to end at each side of the central portion 42 in the direction of reciprocation of said cross head. -The thrust surfaces of the cross heads also are provided with lubricant retaining cross grooves 44.

The cylindrical porti n of each piston unit comprises a sleeve 45 which is counter-bored to receive the head 46 of a securing shank screw 47, each sleeve and screw being so proportioned that a clearance is providedbetween the outer wall of the screw and the inner wall of the sleeve. The clamping face 48 of the screw head 46 is shaped to form a part of a sphere and the screw 47 is threaded into a receiving tap 49 formed in the cross head or block 41 so that when the screw head 46 is tightened in the sleeve counter bore said sleeve will be secured to the cross head with the thrust end 50 thereof tightly clamped against said cross head. Each sleeve 45 also is internally threaded to r ceive an end plug 51 which closes the end of the sleeve and thus provides (in effect) a solid piston or plunger. The plugs 51 engage lock washers 52 interposed between said plugs and the outer ends of the respective screw heads 46.

A valve of the spool or dumbbell type is reciprocable in each valve bore 20 and includes a pair of heads 53 spaced apart and connected by a reduced shank 54. It will be observed by reference to Figures 1, 3 and 11 that the heads 53 are spaced apart a distance equal to or slightly less than the distance between the associated pair of relief ports 23 so that it is possible to centrally position the valve so that the heads thereof will close off communication between the associated duct 26 and both of the fluid chambers 12 and 13. It will, therefore, be apparent that the valves operate to alternately open and close communication into and from the respective fluid chambers 12 and 13.

As will be observed by reference to Figures 1 and 11, the valves are axially bored as at 55 and counter-bored as at 56 to reduce the weight thereof and provide for equalization of pressure areas at the respective ends thereof. The counter-bore at the inner end of each valve serves to accommodate an anti-friction ball 57 and the counterbore at the outer end of each valve cooperates with the respective cup plug 21 in mounting a compression spring 58 designed to hold the valve with its anti-friction ball 57 always in contact with the eccentric portion 31 of the impeller shaft.

In operation, as the impeller shaft 27 is rotated, the eccentric portion 31 thereof will cooperate with the compression springs 58 in imparting reciprocation to the control valves, and will cause the heads 53 thereof to alternately close and open communication between the piston bores and the respective fluid chambers 12 and 13. During half a revolution of the impeller shaft communication will be afforded between the inlet passage 13 and a given piston bore and communication with the outlet chamber 12 will be closed, and during the remaining half revolution communication will be afforded between said piston bore and the outlet fluid passage 12 and communication thereof with the inlet or suction fluid chamber 13 will be closed.

Rotation of the eccentric portion 32 of the impeller shaft will act through the ring 33 in a manner well known in this art to impart reciprocation to the pistons connected to said ring through the medium of the cross-heads 41 and the tangential grooves 36. It will be understood that the cross heads 41 will reciprocate tangentially in the grooves 36 and the slightly inclined bearing surfaces 43 of the cross head will serve to build up a very efficient high pressure lubricant film bearing between said cross head and theopposing thrust face 38 of the ring 33.

As will be evident by reference to Figure 4 of the drawings, the valve actuating eccentric portion 31 is positioned 90 degrees ahead in phase relation with the piston actuating eccentric portion 32, and in this manner each time a piston or plunger reaches a dead center position the associated control valve will be positioned in neutral with the heads 53 thereof closing off communication between the communicating duct 26 and both fluid chambers 1;. and 13. It will be understood, of course, that as continued rotation of the eccentric portion 32 starts to move the piston inwardly or outwardly from its previous dead center position, the valve previously positioned in neutral will be moved so that one head thereof will continue to close off communi-. cation between the duct 26 and one of the fluid chambers and the other head thereof will move to open communication between that duct and the remaining fluid chamber as may be proper fectly balanced operation is assured and the parts are not subjected to wear and strain to which like parts in conventional forms of this type of pump are subjected.

By reason of the peculiar construction of the piston or plunger units as shown in Figures 2, 9 and 10,- a somewhat elastic construction is provided whereby the piston plunger is enabled to align itself in its bore without afiecting the position of its associated cross head, the construction of the securing screw 46, 47- and the clearance surrounding the screw and also the lock washer permitting the slight movement necessary for this alignment.

From the foregoing description taken in connection with the accompanying drawings, it is thought that'the novel details of construction, the manner of use and the advantages of our invention will be readily apparent to those skilled in the art to which it relates.

We claim:

1. In a pump, a self-aligning piston and cross head assembly comprising a head block having a threaded bore in one face thereof, a sleeve having a counterbore forming an abutment shoulder and a headed screw within the sleeve having a diameter slightly less than the internal diameter of the sleeve and adapted to thread into the block bore whereby the screw head will engage the abutment shoulder and secure the sleeve to the block.

2. In a pump, a self-aligning piston and cross head assembly comprising a head block having a threaded bore in one face thereof, a sleeve having counterbore forming an abutment shoulder,

and a headed screw within the sleeve having a diameter slightly less than the internal diameter of the sleeve and adapted to thread into the block bore whereby the screw head will engage the abutment shoulder and secure the sleeve to the block, said screw head having an abutment shoulder engaging face corresponding to a portion of a sphere.

3. In a pump, a self-aligning piston and crosshead assembly comprising a head block having a threaded bore in one face thereof, a sleeve having a counterbore forming an abutment shoulder, a headed screw within the sleeve having a diameter slightly less than the internal diameter of the sleeve and adapted to thread into the block bore whereby the screw head will engage the abutment shoulder and secure the sleeve to the block, said sleeve being internally threaded beyond the shoulder thereof, a plug screw seemed in the threaded end of the sleeve, and a spring lock washer interposed between said plug and said screw head.

4. In a pump, a self-aligning piston and cross head assembly comprising a head block having a threaded bore in one face thereof, a sleeve having a counterbore forming an abutment shoulder, a headed screw within the sleeve having a diameter slightly less than the internal diameter of the sleeve and adapted to thread into the block bore whereby the screw head will engage the abutment shoulder and secure the sleeve to the block and'said screw head having an abutment shoulder engaging face corresponding to a portion of a sphere, said sleeve being internally threaded beyond the shoulder thereof, a plug screw secured in the threaded end of the sleeve, and a spring lock washer interposed between said plug and said screw head.

ELEK K. BENEDEK. HOWARD FL MACMILLIN. 

